...and cheaper, more convenient, more reliable, faster delivery, much larger footprint (depending on paging infrastructure of course, but in Australia extensive). etc etc.
I suspect that data encryption was a major factor in emergency services moving away. Certainly wasn't cost - replaced with much more expensive mobile phone based messaging (heavy ruggedised phones - 2 phones per person, 1 on each carrier activated simultaneously in case one didn't work:-) )
Cheers
...Steve